And, if you want partners, get there via the Moon.

Back in 2010, the bill authorizing funding for NASA directed the agency to contract for an analysis of its long-term plans for human spaceflight. Four years later, the organization that received the contract, the National Academies of Science (NAS), has finally released the report.

That may seem like a painful delay, but the NAS has, like many others, determined that NASA's budget really isn't able to support a long-term plan for exploration anyway, so there wasn't really a rush to figure out where we're going. And the report took a while because the experts organized by NAS stepped back from the immediate problem and looked at the question of what we hope to accomplish from having a manned space program in the first place.

It found there was no single, compelling reason for extending human exploration beyond low-Earth orbit (LEO). But, with the right destination, a collection of less than fully compelling reasons could add up to a strong justification for manned space flight. And that destination is Mars.

The big picture

Just like anyone else who has looked at the problem has concluded, budget instabilities and changing priorities have made it difficult to pursue human exploration beyond low-Earth orbit. It traces these instabilities to the US public itself. The people who care about space exploration care passionately about it, but the great majority of the US public is indifferent unless there's something in the news (and sometimes indifferent even then).

Given that indifference, the authors of the report examined the usual collection of justifications given for human space exploration. Some of these are pragmatic: the economic return on federal R&D spending, the benefits for national defense, etc. But the authors found that there was little need to go beyond low-Earth orbit to get most of these benefits, and it was impossible to weigh the benefits of space exploration in comparison to other federal R&D programs. So, they looked at aspirational goals as well. The space program does attract people to science and technology fields, but so do robots like Curiosity and Cassini. And, at this point, it's impossible to tell whether space exploration could ever give our species an enduring presence somewhere other than Earth.

"No single rationale alone seems to justify the value of pursuing human spaceflight," the report states. "[But] the aspirational rationales, when supplemented by the practical benefits associated with the pragmatic rationales, do, in the committee’s judgment, argue for a continuation of our nation’s human spaceflight program."

So, rather than focusing on any specific benefit, the NAS stepped back and identified what it termed "the enduring questions for human spaceflight: How far from Earth can humans go? and What can humans do and achieve when we get there?" Any manned space program should be focused on providing us some answers to these questions.

To answer them, we need a sustainable program of exploration beyond low-Earth orbit. And, to direct this sort of program, we need what the NAS termed a "horizon goal," something that would both give us a partial answer to the two big questions and provide a framework for an entire exploration program. And, of all the potential horizon goals that are currently available to us, the only target that does this is landing on the surface of Mars.

Tackling Mars

The US would have an extremely difficult time arranging the money to put a human on Mars before the century is out. Having partners would make it much easier to achieve. Although the authors of the report don't use the term, it's clear they think we're being a bit stupid for not including the Chinese among those on our list of potential partners. China's exploration program is sustained, incremental, and methodical—exactly the sorts of things the authors feel we should be aiming for with our own program.

Beyond that, there's a conflict of goals. As far as the current administration is concerned, the US program is currently focused on visiting an asteroid, either in situ or one returned to an orbit near the Moon. Almost all of the potential partners we have for extended exploration in space are completely indifferent to that goal. Most of them, in contrast, are interested in a sustained exploration of the Moon, possibly including a base. In fact, a base provides many benefits, since it will give us experience that should allow us to extend our first visit to Mars long enough to accomplish significant science goals (and provide a more satisfying answer to "what will we do when we get there?").

This would seem to create a binary choice: if we want partners (and we most certainly do), we need to go to the Moon. If we want to go to an asteroid, we won't have partners.

But the report argues that's really a false choice. To go to Mars safely, we need a sustained program that includes (relatively) frequent launches: "the current program to develop launch vehicles and spacecraft for flight beyond LEO cannot provide the flight frequency required to maintain competence and safety." That way, we can maintain expertise between missions and fully understand the properties of our vehicles before we start using them for long-distance human travel. This means multiple trips beyond low-Earth orbit—enough to accommodate trips to both the Moon and one or more asteroids.

Having multiple goals will also be useful for allowing what the report terms "exit ramps." Essentially, these are intermediate destinations like the Moon or Mars' moons that are part of the overall program to place people on Mars. Should a budget crunch interrupt the exploration program, we should be able to bring the exploration program to a close with a satisfying exploration of a destination short of Mars. This, the authors strongly feel, is much better than keeping the full program hanging around but underfunded.

NASA's launch vehicle hopes are currently pinned to the heavy-lift Space Launch System, or SLS, shown here in a rendering. SLS might take humans to Mars—if it flies at all.

NASA

Can we actually manage this? Not within the current NASA budget, which projects a gradual decline in real dollar terms over the next few years and funds missions that are far too erratic to maintain safety and expertise. At a minimum, doing any serious, sustainable exploration will require increases to NASA's budget that keep pace with inflation (the report uses a 2.5 percent increase a year).

Obviously, more could be done if we had more money. But the report cautions against responding to any extra funding by adding destinations to the program. Instead, it suggests any over-budget funding be used to do what it terms "retire risk"—accelerate technological developments needed for future stages of exploration. This would make the whole program more tolerant to cuts in the future. It would also aid in planning, since it would provide a greater sense of what the hardware would look like.

Overall, the report (like several others before it) makes a tremendous amount of sense. But sense and political reality really have had little to do with each other. In the absence of a strong public consensus about where space exploration should be going, NASA has been treated less as an R&D program and more as a jobs program, both by the representatives of the states where the jobs are, and by the lobbying arms of some of the major companies involved in space flight.

That's unlikely to change unless we can solve the public interest problem. The problems facing the US space program are unlikely to change until more members of Congress care about what happens to the space program, and care from a broader perspective than how much money from NASA's budget goes to their district.

What angers me is that supposedly we are not interested in going to the Moon and want to go to an asteroid.

But I clearly remember Ares 1 -- built in the US, launched in the US, designed to carry a manned US spacecraft, and successfully launched and tested -- with the goal of providing crew launch for an Earth Orbit Rendezvous (EOR) lunar mission!

Seems to me like we're interested in going to the Moon if we're actually building and flying lunar spacecraft.

And yet, all of a sudden, that disappeared from everything NASA says it wants to do and the surviving parts of the program -- the launch tower, for example -- are sitting somewhere at KSC rusting in the Florida salt air. Now it's "too expensive" while we spend trillions of dollars every year on trying to kill people who disagree with us.

As you might guess from my username (the same one I use in other places), I am a passionate space buff... or was, anyway. I have come to the conclusion lately that the planners in the manned spaceflight division at NASA have developed an inability to remember their own actions and plans of just a few years ago.

My priorities are shifting to other interests since my lifelong dreams show no sign of coming to fruition. Why should I care when the people who are charged with carrying them out don't seem to?

at this point, it's impossible to tell whether space exploration could ever give our species an enduring presence somewhere other than Earth.

Fermi Paradox solved. There are no aliens out here because space travel is impractical, uneconomical, and pointless. All intelligent species eventually die in the gravity well of the same star system they were spawned in.

I couldn't help read the NAS report summary as, "To be honest we couldn't come up with any really compelling reasons why manned space flight beyond LEO was actually need. We came up with a number of smaller rationales that when you put them toge...dang it" *throws clipboard down* "BECAUSE MARS! End of rationale. Thank you. I'll take questions later."

We need to go because its in our genes. We left Africa for a reason, because there is something over that hill over there and I'd like to see it. I don't think we as a species can stop some manner of wanderlust and needing to know what is over the hill. I think it would be a bad thing for our species if we/when we do.

So...MARS!

I think the Moon first. I know there are a lot of engineering differences, but I think it would lend some pratical experience in maintaining a prolonged presence away from the immediate ability of resupply as well as help perfect things like ground operations on another body and other engineering and operational bits and pieces (and...BECAUSE MOON!). Then Mars.

I just really hope we get there in my life time (If the Gods are good, that means at least another 50 years (I am hoping for 60 years though)).

And yet, all of a sudden, that disappeared from everything NASA says it wants to do and the surviving parts of the program -- the launch tower, for example -- are sitting somewhere at KSC rusting in the Florida salt air. Now it's "too expensive" while we spend trillions of dollars every year on trying to kill people who disagree with us.

It didn't disappear, it got cancelled and with good reason. Constellation was a Apollo scale program, without an Apollo sized budget.

The Ares I wouldn't have flown until 2019! So in that respect, the commercial crew program that replaced the Ares I has been a way better investment. Not only cheaper, but the commercial crew companies like Space X should be able to fly Americans to space in an American spacecraft again by 2016-2017.

As for going to the moon, or Mars. There simply isn't a budget for that, and hasn't been. You want someone to blame? Don't blame NASA or the Politicans. Blame the American people.

If you ask Americans in a poll if they think NASA is important, they will say yes. If you ask Americans in a poll whether they think the US should continue to lead, they will also say yes. If you ask them though, if NASA's funding should go up from sequester levels. Only 10 percent will say yes.

Or in other words, Americans think the space program is important. They just don't want to fund it.

"The US would have an extremely difficult time arranging the money to put a human on Mars before the century is out."Really you do not not think that we can fly to Mars in 86 years!

Probably not, if the US insisted on keeping it an American endeavor and not make it a global one. Too expensive to do the bulk of the research and manufacturing for a country even as rich as the US. Going to Mars should be the goal of humanity itself, not just one nation.

I would have liked to have seen that much like those living in the 60s watched the moon landings...

While a landing by NASA seems no better a chance than any time in the last thirty years, one by private endevours is at least seeming to have a glimmer of hope.

I agree that Space X could probably make a manned Mars trip happen on NASA's current budget. We should kill SLS, and fund Space X's more detailed plan to get to Mars and sooner than NASA would otherwise do.

"The US would have an extremely difficult time arranging the money to put a human on Mars before the century is out."Really you do not not think that we can fly to Mars in 86 years!

Probably not, if the US insisted on keeping it an American endeavor and not make it a global one. Too expensive to do the bulk of the research and manufacturing for a country even as rich as the US. Going to Mars should be the goal of humanity itself, not just one nation.

I don't disagree with why it should be multinational...but...uh, most studies peg the overall cost of getting to Mars (and back, that part is important) in the few hundred billion range. Like, a small fraction of the cost of just the Iraq war. Combined with the fact that we have the science and general engineering know how to do it now, let alone improving upon all of that. So, within 86 years if we really wanted to and were willing to dedicate the necessary resources to, heck yeah. If we were willing to dedicate the resources starting now, we could probably do it before 2030.

As is, we'll probably be lucky if it is by 2040, but I suspect when it happens it'll be an astronaught planting a flag in the newly named Musk crater after stepping off a SpaceX lander (and that's okay by me).

It found there was no single, compelling reason for extending human exploration beyond low-Earth orbit (LEO).

Sure, because it's not like we're running out of resources here, or that our species is in danger (in the long run) of dying out on this planet. /sarcasm

No compelling reason? Really? How about expanding our knowledge of the universe? How about expanding our reach into the solar system? The solar system should be our back yard by now. How about ensuring the future of the human race? What happened to the pioneering spirit?

It's so sad that the only thing we seem to want to spend money on is blowing up poor brown people half-way around the globe.

I remember the same negative arguments regarding Apollo, but they never won the day. The spirit behind the Apollo missions, as well as Mercury and Gemini before them, was that they inspired us. We had heroes. Every step was thrilling: Space flight! Earth orbit! Circle the moon! (Apollo 8 - my favorite - the pictures of earthrise) Those first steps! Even the tense waiting for Apollo 13.

Then, along about Apollo 15, it got to be mundane. Then the shuttle program made it boring. I am afraid Mars will never inspire us like those first trips to the moon.

The report's primary recommendation is good, as an aspirational goal. Additional goals, more affordable in the short term and far more incremental with abundant off-ramps, would aim toward colonization of space in general. Whether pure colonialism, asteroid mining, military competence building, tourism, or economic engine building; the launchers, spacecraft, habitats, and cultural components are ultimately going to be applied whether off-world or on another moon or planet. Continued development of launchers and habitats, as is being done now, are foundational and critical. Partners and expanded funding would be great, but development of infrastructure, technique and technology will all have to be done, no matter what horizon or empire is the final goal. The President broke my heart when the recession gave him every reason to pour billions into this future by executive effort, and then failed to use his considerable rhetorical skills to do so.

What angers me is that supposedly we are not interested in going to the Moon and want to go to an asteroid.

But I clearly remember Ares 1 -- built in the US, launched in the US, designed to carry a manned US spacecraft, and successfully launched and tested -- with the goal of providing crew launch for an Earth Orbit Rendezvous (EOR) lunar mission!

Ares I was never completed and tested. Ares I-X, which was quite far from the full-up Ares I spacecraft was, but the whole thing was never finished; the test launch was an incomplete (four-segment SRB, versus the final vehicle's 5-segment booster) first stage launching a mass simulator, which is basically nothing as far as a real vehicle is concerned. It would have required a huge amount of effort to turn into a workable vehicle.

Seems to me like we're interested in going to the Moon if we're actually building and flying lunar spacecraft.

We were, in 2007, when the Bush Administration (which came up with the whole idea of going back to the Moon) was still in office. By 2009, it was mostly inertia, sunk costs, and the lack of anything better to do (since the Augustine Report wouldn't be released until just 6 days before the flight) that was keeping the thing going. It was pretty obvious that the Obama administration, like every presidential administration, was raring to put its own stamp on the program, and given how terribly Constellation was going, there was zero chance it was going to survive.

And yet, all of a sudden, that disappeared from everything NASA says it wants to do and the surviving parts of the program -- the launch tower, for example -- are sitting somewhere at KSC rusting in the Florida salt air. Now it's "too expensive" while we spend trillions of dollars every year on trying to kill people who disagree with us.

Yes, we do spend hundreds of billions of dollars a year on the military; however much you would rather this be spent on space exploration (I most certainly would), though, this isn't going to change. The United States Congress has more or less accepted a funding level of about $15 to $20 billion a year for NASA, so any program had better fit reasonably in that. If you want more, you really need to get people interested in giving more money, to the point of lobbying, but that approach hasn't worked since space advocacy started 40 years ago, so I doubt it will work any time soon.

For this reason, Constellation was a non-starter. Most of that budget is already spoken for by other things, such as scientific research (for example, into aeronautics), preexisting missions (like the ISS), or non-human spaceflight, so only a limited amount of it can be tapped by any future program. Costs for Constellation (or SLS) were so large that it would require all of that limited amount for a long period of time to develop and launch, which is highly unreasonable. It was entirely possible that the minimum amount of money needed in some years (just for basic things like supporting missions while continuing R&D for future missions) was going to be greater than the amount of money it was possible to tap in that year.

Since it was his program, Bush of course didn't do anything this. Obama did recognize this, and proposed an alternate program that, while it would have put off exploring, would have tried to develop capabilities and reduce costs for the future, for example by supporting the development of a commercial space agency (Obama has always proposed much higher budgets for the Commercial Crew Program than Congress has actually allocated). Congress mostly didn't care, but didn't like Obama's approach because it didn't mean jobs for Marshall and Stennis, hence forced the SLS on NASA. Unfortunately, the SLS has the same disadvantages as Constellation, namely being very expensive and therefore launchable only rarely.

As you might guess from my username (the same one I use in other places), I am a passionate space buff... or was, anyway. I have come to the conclusion lately that the planners in the manned spaceflight division at NASA have developed an inability to remember their own actions and plans of just a few years ago.

Their boss is the President; this is literally his fault. Obama clearly does not want a lunar return, and obviously is not particularly interested in spaceflight, both of which are fair enough; he does have a lot else to do. Because of that, though, talking about publicly it is a tad verboten, although there are strong signs that people in NASA are continuing to think about lunar return anyways.

My priorities are shifting to other interests since my lifelong dreams show no sign of coming to fruition. Why should I care when the people who are charged with carrying them out don't seem to?

They're mostly doing the best they can in the environment they have to deal with. If they don't seem to care, it's because you look at them and cannot perceive the bars of their prison.

Anyways, I wanted to point out that people are really too hard on the asteroid mission(s); I don't think they quite understand the point of them, which is not science, but engineering. Just like the Apollo missions required multiple engineering missions with little scientific content before they could be launched, such as the Gemini missions and Apollos 7 through 10, any Mars missions will require flights to verify and test key systems and approaches like life support, in-situ resource utilization, and aerocapture. These asteroid missions do this--in the case of the asteroid capture mission, it tests high-power electric propulsion, automatic rendezvous, and large-scale deep-space solar power, all of which would be useful for a cargo mission dispatched to Mars ahead of a human mission, for example--in a safer and simpler environment than Mars itself, while adding some scientific content. Traditionally (I mean in the 1960s and a lesser extent the 1970s and 1980s), these engineering objectives would have been addressed by a Mars flyby, which would be completely scientifically worthless nowadays. Additionally, there is considerable interest in using Mars' moons, which are essentially asteroids, in a Mars mission (Fred Singer, for instance, has been selling what he calls the PhD mission for thirty years). The technologies and techniques needed for an asteroid mission would be directly applicable here. The idea is really much cleverer than many people, particularly Congress, give NASA credit for, and I think much of the criticism is based on fundamentally incorrect notions of the mission development and launch process.

I would have liked to have seen that much like those living in the 60s watched the moon landings...

Well at least not a landing by NASA. In the current climate I would not be surprised to see private industry begin to outpace NASA, especially if the more ambitious asteroid mining ventures become lucrative. Look how quickly SpaceX developed the Dragon, they only began developing it a decade ago and are already poised to launch a man-capable capsule. By not being bogged down with bureaucracy private industry is able to innovate and will be forced to innovate with the changing landscape; The ISS is set to be decommissioned in 2020, if SpaceX wants to stay in business they will need something to launch to, a new international station? a privately operated space resort? a full scale space mining operation? who knows what the future holds but I doubt they will let their investments go to waste. Also the Chinese space program is just ramping up, we could see another full-scale space race take place over the next 50 years. Maybe I am being overly optimistic but I feel that saying "well if NASA cant do it then no one will" is not giving enough credit to the rest of the world.

What we need to do is convince Congress that the Russians or the Chinese (or, fuck it, teh terrarists) are going to get to Mars first and somehow militarize it; that might shake loose some funding.

Otherwise, forget about it.

Besides, it's the unmanned program that's got the non-geek public jazzed. The MERs, MSL, Cassini, et al. are what's driving public interest. We should be investing more in robotic probes; they give us far more bang for the buck. For the cost of a single manned mission to Mars, you could pepper the surface with MER-style rovers.

Beyond that, it's not like there are many places we can put boots down beyond Luna or Mars. Mercury and Venus are non-starters, as are the gas giants themselves. We could theorertically land people on Europa or Titan, although not without serious advances in long-term spaceflight.

I (like virtually everyone else) will not be flying into space. It makes little difference to me that the pictures and scientific measurements were taken by a man or a robot and since we can send 100 robots into space for the same price as one man...give me a robot every time.

"The US would have an extremely difficult time arranging the money to put a human on Mars before the century is out."Really you do not not think that we can fly to Mars in 86 years!

Probably not, if the US insisted on keeping it an American endeavor and not make it a global one. Too expensive to do the bulk of the research and manufacturing for a country even as rich as the US. Going to Mars should be the goal of humanity itself, not just one nation.

I don't disagree with why it should be multinational...but...uh, most studies peg the overall cost of getting to Mars (and back, that part is important) in the few hundred billion range. Like, a small fraction of the cost of just the Iraq war. Combined with the fact that we have the science and general engineering know how to do it now, let alone improving upon all of that. So, within 86 years if we really wanted to and were willing to dedicate the necessary resources to, heck yeah. If we were willing to dedicate the resources starting now, we could probably do it before 2030.

As is, we'll probably be lucky if it is by 2040, but I suspect when it happens it'll be an astronaught planting a flag in the newly named Musk crater after stepping off a SpaceX lander (and that's okay by me).

A manned mission to Mars for a few hundred billion? Maybe. It's possible, but no, we don't have the engineering know-how to do it right now. Radiation shielding alone is a huge, and so far unsolved, problem (even on the ISS radiation dosages are pretty high: interplanetary space is a lot worse). We don't yet have the engineering to land a manned pod on Mars: Curiosity was already technically challenging, and a manned pod would have to be much much larger.

And returning? Forget about it. That at least doubles the size of the ship you have to send. You can leave a transit stage in orbit, but you still need fuel to return from the surface.

Look at it this way: the ISS cost over $100 billion. A Mars mission would require at least that much equipment, vastly more consumables (food/water/O2 for the entire crew for 3+ years), and would need to be sent much much (much much) further, land in a thin atmosphere, and then return again. I wouldn't be surprised if the actual cost ran into the trillion or more range.

Maybe when SpaceX gets launch costs way way down we can start looking at a mission there. Returning to the Moon, maybe with a semi-permanent base, is a vastly easier goal. A manned Mars mission, however, is simply outside our current technological know-how without an absolutely massive expenditure of resources (for relatively little scientific gain: the biggest gain would probably be the technology developed to get there in the first place).

$18 Billion a year is not enough to do what they're being asked to do. NASA is pretty much screwed and handy capped by perpetual inadequate budgets. With goals changing every 4 years how can an organization who's aspirations can take decades to succeed possible continue to compete with economic powerhouses with laser focus? It's not going to take long for China to pass the US in space. They have the computer technology, engineering and money NASA could only dream about when they went to the moon. Their advancement has been incredibly swift.

It should be noted, that going to Mars even on the high range of 500 billion is still affordable (Though, I believe it can be cheaper with fuel depots/the Space X approach). That is 500 billion over 20/30 years, partner with the ESA and make them pay half and that's 12 billion a year for 20 years at the least. Its doable.

Keep in mind, as consumers we spend 60 billion dollars a year on our pets. 90 billion dollars a year on booze. 100 billion dollars a year on illegal drugs. Going to Mars was never about a lack of money, always about a lack of will.

Anyway, I just wanted to make it clear that the myth that its too expensive is total BS. Expensive compared to what? The bank bailouts? Nah. Two wars with a questionable benefit to the American people? Hell no.

Maybe the Americans should think less about killing other people and occupying foreign countries and more about science, education, technology, and research. Then, the Americans might have enough money and knowledge to go to the Moon, first, and then from there start exploring other parts of the Solar System.

Being an economist I always tend to think that if humanity could just set aside frivolous political, social and religious conflicts, exuberance, over-speculation and all of the other stuff stopping us from making rational decision as a species, we would be able to accomplish amazing things within my lifetime.

Anything that gets us closer to that state, including space exploration projects across nations, I wholeheartedly support.

I (like virtually everyone else) will not be flying into space. It makes little difference to me that the pictures and scientific measurements were taken by a man or a robot and since we can send 100 robots into space for the same price as one man...give me a robot every time.

So you don't see the value in pushing the limits of our capabilities as a species?

We need to leave manned space flight to the commerical sector. That's most appropriate.Just look at what the astronauts are doing on thespace station now. Not much. That frees thelimited public funds for real interplanetary sciencevia robotic missions. We have to face that we area declining empire (in more ways than one) and willnot have the funds to pursue manned space flightthrough the public sector. A declining empire can notrealize all dreams. (Just ask the Romans, the British,etc.)